Using ILI surveillance to estimate state-specific case detection rates and forecast SARS-CoV-2 spread in the United States

Justin D Silverman; Alex D Washburne

Across the entire US, the doubling rate for deaths due to COVID is 3.01 days (±0.001, pvalue of test that doubling rate is less than 3.5 days approximately 0). Under a 1-day lag from the onset of infectiousness to reporting as ILI, the doubling time of deaths in the US imply an expected 98.6% clinical rate (the proportion of patients who have symptoms for which they would 120 present to a health care provider) if the entirety of the first week of ILI surge is comprised of COVID patients ( Figure 3A ). Adjusting the ILI surge to account for decreased care-seeking does not produce congruence between the epidemic curve and the ILI surge, suggesting additional factors can be affecting the ILI surge, such as successful interventions, even faster decreases in care-seeking than observed in New York, or epidemic growth rates faster than 3 days.